package org.moxie;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

/**
 * Describes a restriction in versioning.
 * 
 * @author <a href="mailto:brett@apache.org">Brett Porter</a>
 * @version $Id: Restriction.java 997380 2010-09-15 16:08:51Z bentmann $
 */
public class Restriction {
	private final ArtifactVersion lowerBound;

	private final boolean lowerBoundInclusive;

	private final ArtifactVersion upperBound;

	private final boolean upperBoundInclusive;

	public static final Restriction EVERYTHING = new Restriction(null, false, null, false);

	public Restriction(ArtifactVersion lowerBound, boolean lowerBoundInclusive, ArtifactVersion upperBound,
			boolean upperBoundInclusive) {
		this.lowerBound = lowerBound;
		this.lowerBoundInclusive = lowerBoundInclusive;
		this.upperBound = upperBound;
		this.upperBoundInclusive = upperBoundInclusive;
	}

	public ArtifactVersion getLowerBound() {
		return lowerBound;
	}

	public boolean isLowerBoundInclusive() {
		return lowerBoundInclusive;
	}

	public ArtifactVersion getUpperBound() {
		return upperBound;
	}

	public boolean isUpperBoundInclusive() {
		return upperBoundInclusive;
	}

	public boolean containsVersion(ArtifactVersion version) {
		if (lowerBound != null) {
			int comparison = lowerBound.compareTo(version);

			if ((comparison == 0) && !lowerBoundInclusive) {
				return false;
			}
			if (comparison > 0) {
				return false;
			}
		}
		if (upperBound != null) {
			int comparison = upperBound.compareTo(version);

			if ((comparison == 0) && !upperBoundInclusive) {
				return false;
			}
			if (comparison < 0) {
				return false;
			}
		}

		return true;
	}

	@Override
	public int hashCode() {
		int result = 13;

		if (lowerBound == null) {
			result += 1;
		} else {
			result += lowerBound.hashCode();
		}

		result *= lowerBoundInclusive ? 1 : 2;

		if (upperBound == null) {
			result -= 3;
		} else {
			result -= upperBound.hashCode();
		}

		result *= upperBoundInclusive ? 2 : 3;

		return result;
	}

	@Override
	public boolean equals(Object other) {
		if (this == other) {
			return true;
		}

		if (!(other instanceof Restriction)) {
			return false;
		}

		Restriction restriction = (Restriction) other;
		if (lowerBound != null) {
			if (!lowerBound.equals(restriction.lowerBound)) {
				return false;
			}
		} else if (restriction.lowerBound != null) {
			return false;
		}

		if (lowerBoundInclusive != restriction.lowerBoundInclusive) {
			return false;
		}

		if (upperBound != null) {
			if (!upperBound.equals(restriction.upperBound)) {
				return false;
			}
		} else if (restriction.upperBound != null) {
			return false;
		}

		if (upperBoundInclusive != restriction.upperBoundInclusive) {
			return false;
		}

		return true;
	}

	public String toString() {
		StringBuilder buf = new StringBuilder();

		buf.append(isLowerBoundInclusive() ? "[" : "(");
		if (getLowerBound() != null) {
			buf.append(getLowerBound().toString());
		}
		buf.append(",");
		if (getUpperBound() != null) {
			buf.append(getUpperBound().toString());
		}
		buf.append(isUpperBoundInclusive() ? "]" : ")");

		return buf.toString();
	}
}
